CZAPEK-DOK MODIFIED BROTH
CAT Nº: 1250
For the cultivation of fungi and bacteria using sodium nitrate
as a sole source of nitrogen
FORMULA IN g/l
Sucrose
30.00
Potassium Chloride
0.50
Sodium Nitrate
3.00
Magnesium Glycerophosphate
0.50
Dipotassium Sulfate
1.00
Ferrous Sulfate
0.01
Final pH 6.8 ± 0.2 at 25ºC
PREPARATION
Suspend 35 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation.
Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at 121°C
for 15 minutes. The prepared medium should be stored at 2-8°C. The color is colorless, and may present a slight
precipitate.
The dehydrated medium should be homogeneous, free-flowing and clear beige in color. If there are any physical
changes, discard the medium.
USES
CZAPEK-DOX MODIFIED BROTH is commonly used for the cultivation of fungi and Candida albicans.
It is similar to Czapek-Dox Modified Agar (Cat. 1015), without the agar, and is used to grow bacteria and fungi which are
capable of using Sodium nitrate as a sole source of nitrogen.
Czapek-Dox Modified Broth is a semi-synthetic medium containing Sodium nitrate as a sole source of nitrogen. It has the
advantage of a chemically defined formulation, which has been modified in its original formula by substituting
Magnesium sulfate and Potassium phosphate with the Magnesium glycerophosphate to prevent the precipitation of
Magnesium phosphate. The medium is elaborated with inorganic sources of nitrogen and chemically defined sources of
carbon only. It is useful in a variety of microbiological procedures, including soil microbiology, and fungi and mold
resistance tests. This medium will yield moderately good growth of most saprophytic Aspergilli.
Sucrose is the sole fermentable carbohydrate providing carbon and energy. Sodium nitrate is the sole nitrogen source.
Potassium salts act as a buffer system. Potassium chloride contains essential ions. Magnesium glycerophosphate and
Ferrous sulfate are sources of cations.
Times and temperatures of incubation vary considerably according to the fungi. As a general rule, incubate from 1 - 2
weeks at room temperature (approximately 25°C). Most Penicillium grow best between 20 - 25°C; Aspergillus species
grow well at around 30°C, but Aspergillus fumigatus grows well at 50°C, and C. albicans at 25°C during 24 - 48 hours.
MICROBIOLOGICAL TEST
The following results were obtained in the performance of the medium from type cultures after incubation at a
temperature of 30 ± 2ºC and observed after 1 to 5 days.
Microorganisms
Growth
Aspergillus brasiliensis ATCC 16404
Saccharomyces cerevisiae ATCC 9763
Bacillus subtilis ATCC 6633
Candida albicans ATCC 10231
Good
Good
Moderate
Good
1
LABORATORIOS CONDA, S.A.
www.condalab.com
Staphylococcus aureus ATCC 25923
Inhibited
BIBLIOGRAPHY
Thom y Raper. Manual of Aspergilli. Williams and Wilkins Co. Baltimore Md. 1945.
Smith G. An Introduction to Industrial Mycology 5th Ed Arnold LR London 1960.
STORAGE
25ºC
Once opened keep powdered medium closed to avoid hydration.
2ºC
2
LABORATORIOS CONDA, S.A.
www.condalab.com